Flood Potential Outlook
Issued by NWS Bismarck, ND
Issued by NWS Bismarck, ND
878
FGUS73 KBIS 251939
ESFBIS
NDC001-007-011-015-021-025-029-031-033-037-041-043-045-047-051-053-
055-057-059-061-065-083-085-087-089-093-103-105-260345-
Probabilistic Hydrologic Outlook
National Weather Service Bismarck ND
239 PM CDT Thu Sep 25 2025
...FLOOD AND WATER RESOURCES OUTLOOK...
This Flood and Water Resources Outlook is for the Missouri and James
River basins of North Dakota, covering the period of 28 September
through 27 December, 2025.
The following message has four sections. The first provides some
text on the highlights of this outlook and conditions affecting the
local hydrology. The second section gives the current and historical
risks of flooding as determined by the Ensemble Streamflow Forecast
model of the National Weather Service. The third section gives the
current probabilities for reaching flood stage at the listed
forecast locations. And finally, the fourth section covers the risk
of the river sites falling below the listed stages.
...Flood Outlook Highlights...
All forecast locations in the Missouri and James River basins across
North Dakota are near to somewhat below normal for this time of year.
...Snowpack Conditions...
No snow exists in the Missouri and James River basins of North
Dakota.
...The Missouri and Yellowstone rivers west of Williston...
The headwaters areas for both the Yellowstone and Missouri rivers
are at near normal levels for this time of year.
normal late summer flows.
...Current Drought Conditions...
There are no drought designations within the state of North Dakota.
...Reservoirs and Natural Wetlands...
While the dry spring runoff season was very detrimental to filling
reservoirs and natural wetlands, they have since fared better than
expected in this second half of the year.
...Soil Conditions...
Soil moisture values west of Highway 83 are range from slightly
above normal to slightly below normal for this time of year. East
of Highway 83 the soils down to 100 centimeters tend to be drier
than normal for this time of year.
...Weather Outlook...
The near term 6-10 and 8-14 day weather outlooks strongly favor
above normal temperatures and slightly favor above normal chances
for precipitation. Looking a little longer into the future, the
one-month outlooks for October show North Dakota with equal chances
above normal, near normal, or below normal temperatures and
precipitation.
In Table 1 below, the current (CS) and historical (HS) or normal
probabilities of exceeding minor...moderate...and major flood stage
are listed for the valid time period.
CS values indicate the probability of reaching a flood category
based on current conditions.
HS values indicate the probability of reaching a flood category
based on historical or normal conditions.
When the value of CS is greater than HS...the probability of
exceeding that level is higher than normal. When the value of CS is
less than HS...the probability of exceeding that level is lower
than normal.
...Table 1--Probabilities for minor...moderate and major flooding...
Valid Period: 09/28/2025 - 12/27/2025
: Current and Historical
: Chances of Exceeding
: Flood Categories
: as a Percentage (%)
Categorical :
Flood Stages (FT) : Minor Moderate Major
Location Minor Mod Major : CS HS CS HS CS HS
-------- ----- ----- ----- : --- --- --- --- --- ---
:Pipestem
Pingree 11.0 13.0 15.0 : <5 <5 <5 <5 <5 <5
:James River
Grace City 12.0 14.0 15.0 : <5 5 <5 <5 <5 <5
LaMoure 14.0 16.0 18.0 : 5 <5 <5 <5 <5 <5
:Missouri River
Williston 22.0 24.0 26.0 : <5 <5 <5 <5 <5 <5
:Cannonball River
Regent 22.0 24.0 26.0 : <5 <5 <5 <5 <5 <5
:Cedar Creek
Raleigh 12.0 14.0 16.0 : <5 <5 <5 <5 <5 <5
:Cannonball River
Breien 10.0 20.0 23.0 : 8 10 <5 <5 <5 <5
:Beaver Creek
Linton 12.0 14.0 16.0 : <5 6 <5 5 <5 <5
:Little Muddy River
Williston 10.0 12.0 14.0 : <5 8 <5 <5 <5 <5
:Little Missouri River
Marmarth 18.0 23.0 30.0 : <5 <5 <5 <5 <5 <5
Medora 15.0 18.0 20.0 : <5 <5 <5 <5 <5 <5
Watford City 20.0 24.0 30.0 : <5 <5 <5 <5 <5 <5
:Knife River
Manning 15.0 17.0 20.0 : <5 <5 <5 <5 <5 <5
:Spring Creek
Zap 14.0 18.0 20.0 : <5 10 <5 <5 <5 <5
:Knife River
Hazen 21.0 24.0 25.0 : <5 9 <5 7 <5 <5
:Heart River
Mandan 27.0 33.0 38.0 : <5 <5 <5 <5 <5 <5
:Apple Creek
Menoken 15.0 16.0 17.0 : 7 9 7 8 <5 7
Legend
CS = Conditional Simulation (Current Outlook)
HS = Historical Simulation
FT = Feet
In Table 2 below...the 95 through 5 percent columns indicate the
probability of exceeding the listed stage levels (FT) for the valid
time period.
...Table 2--Exceedance Probabilities...
Chance of Exceeding Stages
at Specific Locations
Valid Period: 09/28/2025 - 12/27/2025
Location 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Pipestem
Pingree 4.7 4.7 4.7 4.7 5.4 8.5 9.9
:James River
Grace City 4.7 4.7 4.7 4.7 4.7 6.9 10.2
LaMoure 8.1 8.1 8.1 8.1 8.1 10.0 13.6
:Missouri River
Williston 15.2 15.2 15.3 15.3 15.4 15.5 15.8
:Cannonball River
Regent 4.9 4.9 5.1 5.2 6.8 7.9 8.2
:Cedar Creek
Raleigh 1.0 1.0 1.0 1.7 3.4 5.7 6.3
:Cannonball River
Breien 2.3 2.3 2.3 3.5 6.1 9.2 11.2
:Beaver Creek
Linton 4.5 4.5 4.5 4.7 7.2 9.6 11.1
:Little Muddy River
Williston 4.5 4.5 4.5 4.5 5.0 6.0 6.9
:Little Missouri River
Marmarth 0.9 0.9 0.9 0.9 1.4 2.3 3.6
Medora 2.0 2.0 2.0 2.0 2.5 5.1 5.8
Watford City 7.3 7.3 7.3 7.3 7.9 11.0 11.6
:Knife River
Manning 6.2 6.2 6.2 6.2 7.3 9.0 9.0
:Spring Creek
Zap 4.8 4.8 4.8 4.8 5.9 7.4 9.7
:Knife River
Hazen 0.6 0.6 0.6 0.8 5.7 9.2 16.9
:Heart River
Mandan 9.7 9.7 9.7 9.7 11.4 18.2 19.7
:Apple Creek
Menoken 5.6 5.6 5.6 5.6 6.6 11.9 16.2
In Table 3 below...the 95 through 5 percent columns indicate the
probability of falling below the listed stage levels (FT) for
the valid time period.
...Table 3--Nonexceedance Probabilities...
Chance of Falling Below Stages
at Specific Locations
Valid Period: 09/28/2025 - 12/27/2025
LOCATION 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:Pipestem
Pingree 4.7 4.7 4.7 4.7 4.7 4.7 4.7
:James River
Grace City 4.6 4.6 4.5 4.5 4.5 4.5 4.5
LaMoure 8.0 7.8 7.4 7.4 7.4 7.4 7.4
:Missouri River
:Cannonball River
Regent 4.7 4.7 4.7 4.7 4.7 4.7 4.7
:Cedar Creek
Raleigh 1.0 0.9 0.7 0.6 0.6 0.6 0.6
:Cannonball River
Breien 2.2 2.2 2.1 2.1 2.1 2.1 2.1
:Beaver Creek
Linton 4.5 4.5 4.4 4.4 4.3 4.3 4.3
:Little Muddy River
Williston 4.3 4.3 4.3 4.3 4.3 4.3 4.3
:Little Missouri River
Marmarth 0.8 0.8 0.8 0.8 0.8 0.8 0.8
Medora 1.4 1.4 1.4 1.4 1.4 1.4 1.4
Watford City 7.2 7.1 7.1 7.0 7.0 7.0 7.0
:Knife River
Manning 6.2 6.2 6.2 6.2 6.2 6.2 6.2
:Spring Creek
Zap 4.7 4.7 4.7 4.7 4.7 4.7 4.7
:Knife River
Hazen 0.6 0.6 0.6 0.6 0.6 0.6 0.6
:Heart River
Mandan 9.6 9.5 9.2 9.1 9.1 9.1 9.1
:Apple Creek
Menoken 4.1 4.0 3.5 3.3 3.3 3.3 3.3
These long-range probabilistic outlooks contain forecast values that
are calculated using multiple season scenarios from 30 or more years
of climatological data...including current conditions of the
river...soil moisture...snow cover and 30 to 90 day long-range
outlooks of temperature and precipitation. By providing a range
of probabilities...the level of risk associated with long-range
planning decisions can be determined. These probabilistic
forecasts are part of the National Weather Service`s Advanced
Hydrologic Prediction Service.
Visit our web site weather.gov/bis for more weather and water
information.
The next outlook will be issued by the end of October.
$$
AJS